svelte-check hangs for significant time on some specific .svelte module content

[adamansky]

Describe the bug

Running svelte-check on project with the following .svelte module content:

<script lang="ts">
  ///
  ///
  /// A:
  ///

  import { onMount } from 'svelte';

</script>

causes svelte-check eating 100% of CPU for 15 seconds on i7.

cd ./svelte-check-hangs

time  svelte-check 

real    0m14,159s
user    0m15,011s
sys     0m0,117s

To Reproduce
Create TypeScript project add .svelte module with content above.

Expected behavior
svelte-check should process this case within a 1-2 seconds

System (please complete the following information):

• OS: Ubuntu 20.04
• IDE: Any
• Plugin/Package: svelte-check

Additional context
Sample project attached
svelte-check-hangs.tar.gz

PS:
If you add more leading comment slashes /// svelte-check computation time will grow exponentially. Lets try the following example:

<script lang="ts">

  ///
  ///
  ///
  ///
  /// A:
  ///

  import { onMount } from 'svelte';

</script>

[dummdidumm]

It's this regex causing heavy computation.

[mvolkmann]

Maybe there needs to be a step before the content of a file is processed where all comments are removed.

[mvolkmann]

@dummdidumm Thanks so much for this fix! The "Svelte for VS Code" extension is usable for me now!

[JohnnyFun]

fwiw, global replaces to files still gets chuggin pretty good because of formatter. In my case I did a find/replace across 369 files. I let it finish and told vscode to keep waiting. Probably took ~5-10min to finish.

I sometimes also see the formatter chugging on a single, fairly small file.

Btw, thanks for all your guys' recent work on this project!